Browsing by Author "Guven, Aytekin"

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Impaired Coronary Microvascular and Left Ventricular Diastolic Function in Patients with Inflammatory Bowel Disease
(2015) Caliskan, Zuhal; Gokturk, Huseyin Savas; Caliskan, Mustafa; Gullu, Hakan; Ciftci, Ozgur; Ozgur, Gulsum Teke; Guven, Aytekin; Selcuk, Haldun; 0000-0003-2579-9755; 0000-0002-8445-6413; 0000-0002-6463-6070; 25128749; AAJ-8546-2021; JYO-9455-2024; IXD-5147-2023; AAJ-6976-2021; A-7318-2017
Background and aim: Increased incidence of coronary vascular events in patients with inflammatory bowel disease (IBD) is known. However, the association between coronary microvascular function and IBD has not been fully defined. We aimed to investigate whether coronary flow reserve (CFR) and left ventricular diastolic function were impaired in IBD patients. Methods: Seventy-two patients with IBD (36 patients with ulcerative colitis [UC] and 36 Crohn's disease [CD]) were registered. Each subject was evaluated after a minimum 15-day attack-free period. For the control group, 36 age- and sex-matched healthy volunteers were included into the study. IBD clinical disease activity in UC was assessed by the Truelove-Witts Index (TWAS) and in CD by the Crohn's Disease Activity Index (CDAI). In each subject, CFR was measured through transthoracic Doppler echocardiography. Results: Compared to the controls, the CD group and UC group had significantly higher high-sensitivity C-reactive protein (hs-CRP) and erythrocyte sedimentation rate. Baseline diastolic peak flow velocity (DPFV) of the left anterior descending artery (LAD) was significantly higher in the IBD group (24.1 +/- 3.9 vs. 22.4 +/- 2.9, p < 0.05), and hyperemic DPFV (56.1 +/- 12.5 vs. 70.6 +/- 15.3, p < 0.05) and CFR (2.34 +/- 0.44 vs. 3.14 +/- 0.54, p < 0.05) were significantly lower in the IBD group than in the control group. In stepwise linear regression analysis, hs-CRP and lateral Em/Am ratio were independently correlated with CFR. Conclusion: CFR, reflecting coronary microvascular function, is impaired in patients with IBD. CFR and left ventricular diastolic function parameters are well correlated with hs-CRP. (C) 2014 Published by Elsevier Inc.
Increased Morning Blood Pressure Surge and Coronary Microvascular Dysfunction in Patient with Early Stage Hypertension
(2014) Caliskan, Mustafa; Caliskan, Zuhal; Gullu, Hakan; Keles, Nursen; Bulur, Serkan; Turan, Yasar; Kostek, Osman; Ciftci, Ozgur; Guven, Aytekin; Aung, Soe Moe; Muderrisoglu, Haldun; https://orcid.org/0000-0003-2579-9755; https://orcid.org/0000-0002-6463-6070; https://orcid.org/0000-0002-9635-6313; 25224866; IXD-5147-2023; A-7318-2017; AAJ-8546-2021; AAG-8233-2020
Morning blood pressure surge (MBPS) is defined as an excessive increase in blood pressure (BP) in the morning from the lowest systolic BP during sleep, and it has been reported as a risk factor for cardiovascular events in current clinical studies. In this study, we evaluated the association between the rate of BP variation derived from ambulatory BP monitoring data analysis and coronary microvascular function in patients with early stage hypertension. One hundred seventy patients with prehypertension and Stage 1 hypertension who fulfilled the inclusion and exclusion criteria were included in the study. We divided our study population into two subgroups according to the median value of coronary flow reserve (CFR). Patients with CFR values <2.5 were defined as the impaired CFR group, and patients with CFR values >= 2.5 were defined as the preserved CFR group, and we compared the MBPS measurements of these two subgroups. CFR was measured using transthoracic Doppler echocardiography (TTDE). Ambulatory 24-hour systolic and diastolic BP, uric acid, systolic MBPS amplitude, diastolic MBPS amplitude, high-sensitivity C-reactive protein, and mitral flow E/A ratio were statistically significant. These predictors were included in age- and gender-adjusted multivariate analysis; ambulatory 24-hour systolic BP (beta = 0.077, P <.001; odds ratio [OR] = 1.080; 95% confidence interval [CI] [1.037-1.1241) and systolic MBPS amplitude (beta = 0.043, P =.022; OR = 1.044; 95% CI [1.006-1.0841) were determined to be independent predictors of impaired CFR (Hosmer-Lemeshow test, P=.165, Nagelkerke's R-2 = 0.320). We found that increased changes in MBPS values in patients with prehypertension and Stage 1 hypertension seemed to cause microvascular dysfunction in the absence of obstructive coronary artery disease. (C) 2014 American Society of Hypertension. All rights reserved.
The Influence of On-pump Versus Off-pump Surgery on Short- and Medium-term Postoperative Coronary Flow Reserve After Coronary Artery Bypass Grafting
(2016) Ozulku, Mehmet; Caliskan, Mustafa; Saba, Tonguc; Aksu, Feyza; Ciftci, Ozgur; Gullu, Hakan; Guven, Aytekin; Kostek, Osman; Caklili, Ozge Telci; Aslamaci, Sait; 0000-0001-7566-5427; 0000-0002-9635-6313; 0000-0002-1901-5603; 27269474; AAT-7733-2020; AAG-8233-2020; AAA-3604-2019; AAJ-8546-2021
Background Although several clinical trials have compared surgical outcomes between off-pump and on-pump coronary artery bypass grafting (CABG), whether there is a difference in the early- and medium-term postoperative coronary microvascular functions is not fully understood. We compared short- and medium-term coronary microvascular function after off-pump and on-pump CABG. Methods A prospective study of patients undergoing off-pump and on-pump CABG. Eighty-two patients scheduled for CABG were recruited: 38 underwent off-pump surgery and 44 on-pump surgery. Each participant's coronary flow reserve (CFR) and diastolic function were measured with transthoracic Doppler echocardiography six and 12 months after surgery. Results Baseline and hyperaemic diastolic peak flow velocity in the left anterior descending artery were similar in both groups, as was CFR (2.22 +/- 0.66) in the off-pump group compared with (2.13 +/- 0.61) in the on-pump group, (P = 0.54). Coronary flow reserve was significantly and inversely correlated with high sensitivity C-reactive protein concentration (r = -0.416; P < 0.001) and positively correlated with mitral E/ A-wave velocity ratio (r = 0.247; P = 0.02). Stepwise linear regression analysis revealed that only high sensitivity C-reactive protein concentration was independently correlated with CFR (beta = -0.272, P = 0.02). Conclusions Heart-lung bypass technique had no medium-term influence on the coronary microcirculation, despite a possible initial unfavourable effect. Serum hs-CRP concentration was an independent predictor of medium-term coronary microvascular dysfunction.
Radial Artery, Saphenous Vein versus Left Internal Thoracic Artery in Recurrent Ischemic Symptoms after Coronary Artery Bypass Graft Surgery
(2014) Gunday, Murat; Coskun, Isa; Ciftci, Ozgur; Ozulku, Mehmet; Tekindal, Mustafa Agah; Guven, Aytekin; Aslamaci, Sait; https://orcid.org/0000-0002-6463-6070; https://orcid.org/0000-0002-4060-7048; 25065278; A-7318-2017; U-9270-2018; AAJ-8546-2021
Background: The long-term results of coronary artery bypass surgery depend mostly on the type of the grafts. For a long time, it has been accepted that arterial grafts are superior to venous grafts. In this study, we evaluated the angiographic patency rates of arterial and venous grafts. Methods: The study took place between 2003 and 2013 in the Departments of Cardiovascular Surgery in Baskent University. The study included 52 patients with recurrent ischemic symptoms (of total 2183 coronary artery bypass surgery patients) following coronary artery bypass surgery. The patients were evaluated by control angiography during over mid- and long-term postoperative period (mean, 75.25 +/- 35.15 months). Based on the angiographic findings, the grafts were divided into 3 groups: severe stenosis, moderate stenosis, and patent. Results: The preoperative demographics (age, gender, hypertension or diabetes mellitus) were similar in the three groups. The mean numbers of distal anastomoses were 3.27 +/- 0.89 (range 2-5), the degree of native coronary artery stenosis for radial artery anastomosis was 79.65 +/- 17.72, and the mean numbers of radial artery and saphenous vein grafts were 1.19 +/- 0.44 and 1.10 +/- 0.89, respectively. The patency rate was 80.77%for radial arteries, 63.2% for saphenous veins, and 82.4% for left internal thoracic arteries in the three groups. Conclusion: The internal thoracic artery graft was confirmed to be the best option for aorta-coronary bypass surgery, as it has the highest patency rate compared to the other grafts. Radial artery and saphenous vein patency rate were also seen to be similar in the long-term.
Serum Uric Acid and Carotid Artery Intima Media Thickness in Patients with Masked Hypertension
(2014) Caliskan, Mustafa; Guven, Aytekin; Ciftcl, Ozgur; Ozulku, Mehmet; Gunday, Murat; Barutcu, Irfan; https://orcid.org/0000-0002-6463-6070; 25181917; AAJ-8546-2021; A-7318-2017
Background Serum uric acid is related to hypertension and cardiovascular diseases. Masked hypertension is associated with an increase in cardiovascular risk. The aim of our study was to evaluate the serum uric acid level and its relationship with carotid intima-media thickness (IMT) in patients with masked hypertension. Subjects and methods A total of 114 untreated masked hypertension patients (62 men, 52 women; mean age 44.6 +/- 7.9 years) and 38 controls (20 men, 18 women; mean age 44.8 +/- 7 years) were included in the study. All patients underwent 24-hour ambulatory blood pressure. Serum uric acid and carotid IMT were measured. Results Serum uric acid was significantly higher in masked hypertension patients when compared to the control group (5.14 +/- 1.42 mg/dl, 4.84 +/- 1.45 mg/ dl, P=0.01). Masked hypertension patients had significantly higher carotid IMT than control subjects (0.58 +/- 0.09, 0.52 +/- 0.09, P < 0.001). The masked hypertension group was also divided into two groups according to the median value of the serum uric acid levels (median value: 5 mg/dl). Carotid IMT was significantly higher in patients with a higher uric acid when compared to those with a lower uric acid (P < 0.001). We also found that the serum uric acid level was a good predictor of increased carotid IMT at the receiver-operating characteristic curve. The area under the curve was 66% (95% confidence interval, 0.56-0.77), and the serum uric acid level was significantly predictive of a high carotid IMT (P=0.001). Conclusions Our data suggest that the uric acid levels were significantly higher in the masked hypertension group and elevated uric acid levels were associated with increased carotid IMT, indicating that elevated serum uric acid levels might contribute to the increase in cardiovascular risk in masked hypertension.